Patent application WO2015/097314 A1 in the name of the present applicant, discloses a method for detecting identification tags in an area monitored by one or more beacons. An identification tag comprises a magnetic induction module and a transmitter. The identification tag can receive by means of the magnetic induction module a first beacon message as variations in the magnetic field and extract from said message beacon information. Based on said beacon information, the tag can transmit a localization message, preferably by radio frequency, by means of the transmitter.
The system discloses a combination of radio-frequency technology and magnetic induction technology, based on the insight that a localization mechanism is more accurate if magnetic induction is used.
It is a disadvantage of the known system that it does not offer sufficient spatial accuracy. Indeed, the system in WO2015/097314 A1 can falsely detect an identification tag as being present in a particular part of the monitored area, whereas the identification tag is actually located in a different part of the monitored area. Consequently, said tag is then allocated by the localisation system to a wrong part of the monitored area.